TThread5b.java

import java.util.concurrent.locks.*;

public class TThread5b {
    boolean done = false;
    private int count1 = 0, count2 = 0, count3 = 0;

private void init() {
        final ReentrantLock l = new ReentrantLock();
        class Adder extends Thread {
            public void run() {
                while (count1 <= 100) {
                    l.lock();
                    count1++; count2++; count3++;
                    l.unlock();
                    try{
                        Thread.sleep(50);
                    } catch (InterruptedException e) {
                        System.out.println("Application Interrupted");
                    }
                }
                done = true;
            }
        }

class TestSync extends Thread {
            private int totAccess = 0;

public void run() {
                int c1, c2, c3;
                while (!done) {
                    totAccess++;
                    l.lock();

// use the try/catch/finally form if any
                    //    execptions could happen - not needed
                    //    in this case
                    try {
                        c1 = count1; c2 = count2; c3 = count3;
                    } finally {
                        l.unlock();
                    }
                    if ((c1 != c2) || (c2 != c3)) {
                        System.out.println("\rNot synced: " + c1 + ", " + c2 + ", " + c3);
                    }
                }
                System.out.println("Total sync accesses: " + totAccess);
            }
        }

(new Adder()).start();
        (new TestSync()).start();
    }

public static void main(String[] args) {
        TThread5b app = new TThread5b();
        app.init();
    }
}